From the common flu to pathologies requiring intensive and prolonged treatment, medications are often the protagonists of our health. We all take them, whether for short or long periods, and observe their effects. But is their action truly as effective as it could be? Can it be improved? And can we limit side effects? The answers lie in drug delivery.
Why do drugs cause side effects?
Let’s start with a premise: the formulation of the medicine, the pathology to be treated, and the absorption method of the active ingredients determine how the drug is administered. Every dose we take acts differently on our body. Here is how:
- In general, drugs can interact with multiple receptors in our body, reaching the specific site where their action is needed only partially. This leads to accumulation in various organs or tissues, resulting in the notorious side effects characteristic of each drug.
- Drug molecules are often hydrophobic, meaning they do not dissolve well under physiological conditions, or they are susceptible to chemical-physical degradation by enzymes or extreme pH levels.
- Drug administration is not always painless and can sometimes limit a patient’s normal lifestyle.
To address these issues, the common approach is to increase the prescribed dose as much as possible and add excipients, which, in turn, can accumulate and cause unwanted effects. In other words, treating a pathology often comes at a cost in terms of side effects, discomfort, and allergies that may require further medication.
Drug delivery: What it is and how it works
Drug delivery is an evolution of standard administration. It involves the controlled release of a drug over time through fixed implants or nanosystems. By doing so, the total amount of medication needed for a specific treatment period is administered at once, while the matrix protecting the active ingredient preserves its efficacy and guarantees a gradual, controlled release. Today, drug delivery technology competes with traditional oral or injectable methods, offering great benefits to patients by reducing pain, frequency of use, and dosing schedules.
What are the possible applications of drug delivery?
Currently, drug delivery faces many challenges, with cancer treatment being one of the most significant. Every year, more than 12 million new cases are diagnosed worldwide, and research advances alongside the discovery of new drugs and treatment approaches. In the case of chemotherapy, several problems usually arise:
- High toxicity of the molecules;
- Lack of specificity;
- Development of resistance, which lowers therapeutic efficiency.
In this context, drug delivery can make a difference. Nanoparticles loaded with chemotherapy agents, monoclonal antibodies, or radionuclides solve these issues. They allow for:
- Injection into the circulatory system without triggering an immune response;
- Targeting the specific site of the disease;
- Releasing the content inside or in the immediate vicinity of tumor cells.
This makes the treatment more effective while simultaneously decreasing the amount of drug required and the resulting side effects. Furthermore, this technology can significantly reduce a patient’s “clinical cost” by facilitating self-administration. For example, the 2014 proposal by MannKind and Sanofi for spray insulin (later approved by the FDA) for type 1 and type 2 diabetes aimed to make patients more independent by avoiding multiple daily injections.
The future of drug delivery: Nanomedicine
Drug delivery, in the sense of a generic controlled release over time, only partially solves the limitations of traditional administration. Nanomedicine steps in to overcome these remaining obstacles as the natural evolution of drug delivery. Nanostructures do more than just release a drug gradually; they deliver it directly to the site of interest, thereby reducing the dosage and mitigating the side effects of traditional therapies. This resolves the issues related to conventional delivery systems while simultaneously reducing toxicity. This technology will allow us to cross barriers that were once almost inaccessible to standard drugs—such as the blood-brain barrier—and treat ocular pathologies that have always been difficult to manage due to the presence of multiple protective membranes.
Nanotechnology and drug delivery: Application examples
A landmark study by the Mario Negri Institute and the University of Padua recently developed a biocompatible nanocarrier capable of accumulating in the liver to treat hepatic, inflammatory, and autoimmune diseases. A steroid drug, dexamethasone, was encapsulated in a biodegradable nanocarrier, reducing its toxicity and enhancing its therapeutic effect.
Another elegant, entirely Italian application of nanomedicine is designed by EryDel. This biotech company administers drugs by using the patient’s own red blood cells as vehicles. It is an effective solution for circulating a drug throughout all tissues without activating the immune system, specifically aimed at treating a rare neurodegenerative disease in early childhood.
At Nanomnia, we have also managed numerous projects involving the encapsulation of natural and synthetic molecules within biodegradable and biocompatible nanoparticles. Our ultimate goal is always to direct them specifically to the target site or tissue, ensuring the drug is released only where it is truly needed.